Well drilling method and apparatus



Nov. 2, 1965 Filed Sept. 13, 1962 J. E LAQY ETA]. WELL DRILLING METHODAND APPARATUS 5 Sheets-Sheet 1 FIG. I

INVIENTORSI F. F. MARTIN J. E. LACY BY: H -74,

HEIR AGENT Nov. 2, 1965 J. E LACY ETAL WELL DRILLING METHOD ANDAPPARATUS.

S Sheets-Sheet 2 Filed Sept. 13., 1962 FIG.

FIG.

FIG.

INVENTORSI F. F. MARTIN J. E, LACY Y= 4. 14

THEIR AGENT J. E LACY ET AL Nov. 2, 1965 WELL DRILLING METHOD ANDAPPARATUS Filed Sept. 13, 1962 FIG. FIG.

INVENTORS E E MARTIN vJ. E. LACY BY: H.144 c izElR AGENT FIG.

Nov. 2, 1965 J. E- LACY ETAL WELL DRILLING METHOD AND APPARATUS FiledSept. 15, 1962 E l: a

J11? lllll H C F I G IO F IG 9 INVENTORS F. E MARTIN J. E. LACY BY: 6 a

THEIR AGENT Nov. 2, 1965 J. E-ELACY ETAL 1 WELL DRILLING METHOD ANDAPPARATUS Filed Sept. 13, 1952 I 5 Sheets-Sheet 5 FIG. l4

FiG.l2

FIG. l5

FIG. 20

F l G '9 INVENTORS F. F. MARTIN EIR AGENT FIG. I8

United States Patent 3,215,201 WELL DRILLING METHOD AND APPARATUS JohnE. Lacy, Metairie, and Fines F. Mmtin, New 0rleaus, La., assignors toShell Oil Company, New York, N .Y., a corporation of Delaware FiledSept. 13, 1962, Ser. No. 223,368 7 Claims. (Cl. 166-46) This inventionrelates to the underwater drilling of oil and gas wells and pertainsmore particularly to methods and apparatus for installing a conductor orfoundation pipe, or a large-diameter well casing, in an underwater well.

During the recent years, the continued search for oil has resulted indeveloping methods and apparatus for drilling underwater wells atlocations where the water may range from 100 to 1500 feet or more indepth. In these locations it is customary to position the wellheadassembly at a considerable distance below the surface of the water,preferably on the ocean floor, so that it is not a hazard to thenavigation of ships in the area. One method of drilling and completingwells underwater in this manner is described in copending patentapplication, Serial No. 830,538, filed July 30, 1959, and entitledUnderwater Well Completion Method.

One of the most important operations in the drilling of an underwaterwell is that of starting the well and installing the conductor orfoundation pipe in the ocean floor. This operation may be carried out inany one of several ways, two of which are described in US. patents2,929,610 which issued March 20, 1960, to H. Stratton, and US. 2,891,770which issued June 23, 1959, to R. F. Bauer et al. In one method a drillbit drills a hole in the ocean floor slightly larger in diameter thanthe diameter of the well conductor or foundation pipe which issubsequently slipped down along the drill pipe and into the hole duringwhich time drilling fluid is pumped down the drill pipe and up theoutside of the foundation pipe. In another method, a hole is flushed inthe ocean floor for the well conductor or foundation pipe by pumpingfluid down the conductor, allowing it to jet out the lower end thereofto wash a hole in the ocean floor into which the conductor pipe isprogressively lowered. The conductor pipe is then held in place in thehole until the surrounding earth has had time to settle in around theoutside of the pipe and anchor it firmly in the hole.

In certain locations, the above-described methods of starting to drill aWell in the ocean floor and positioning a well conductor or foundationpipe therein are unsatisfactory because of the peculiar soil conditionsof the ocean floor. In certain locations the ocean floor is too soft todrill a hole of shallow depth without the earth caving in and fillingthe hole as fast as it is drilled. Alternatively, if a hole is firstwashed in the ocean floor while lowering a conductor pipe progressivelyinto the hole, there is insuflicient bearing surface or frictionalcontact between the surrounding earth formation that settles into thehole and the outside of the pipe to permit the pipe to support anysubstantial weight.

It is therefore an object of the present invention to provide a methodand apparatus for starting the drilling of an underwater well whereby awell conductor pipe or foundation pipe may be installed in a relativelysoft ocean bottom in a manner so that substantial Weights can besupported on the pipe as the well drilling operations progress.

A further object of the present invention is to provide a method ofinstalling a well conductor or foundation pipe in a soft ocean bottomwhile removing any earth from the interior of the pipe.

Another object of the present invention is to provide apparatus forguiding well drilling equipment from a vessel on the surface of a bodyof water to a well foundation or conductor pipe sunk in the ocean floorso that well drilling operations may be continued after the foundationpipe has been installed.

Still another object of the present invention is to provide a methodwhereby any substantial excess length of conductor pipe or foundationpipe extending above the floor of an ocean may be removed prior tocontinuing drilling operations of the well.

These and other objects of this invention will be understood from thefollowing description taken with reference to the drawing, wherein:

FIGURE 1 is a diagrammatic view taken in longitudinal projectionillustrating the operation of lowering a well pipe from a vessel at thesurface of the water to the ocean floor;

FIGURE 2 is a fragmental longitudinal view of a portion of the vessel ofFIGURE 1 wherein a well pipe is shown as being assembled at the vessel;

FIGURES 3 through 11 are diagrammatic longitudinal views illustratingthe sequential steps of suspending a well pipe from the drilling vesselor platform of FIGURE 1, installing a wash pipe in the well pipe,connecting the wash pipe to the well pipe, adding weights to the wellpipe- Wash pipe combination, lowering the assembled apparatus throughthe water to the ocean floor, forcing the well pipe into the ocean floorwhile washing the loose core from the inside of the well pipe, removingthe weight means from the well pipe and returning them to the barge, andsubsequently lowering a drill bit down to the well pipe at the oceanfloor;

FIGURE 12 is a longitudinal view illustrating the wash head at the endof the wash pipe;

FIGURE 13 is a longitudinal View of one form of a support means carriedby the wash pipe for supporting a well pipe;

FIGURE 14 is an isometric view of one form of a weight platform adaptedto be carried by the wash pipe and derrick against the well pipe;

FIGURE 15 is a fragmenta-l longitudinal isometric view taken in crosssection of a I-slot connector device on the inner wall of the well pipewhich is ada ted to engage the well support device of FIGURE 13 carriedon the outside of the wash pipe;

FIGURE 16 is a longitudinal view, taken partially in cross section,illustrating the support means of FIGURE 13 positioned in the J-slotsection of the well pipe of FIGURE 15;

FIGURE 17 is a longitudinal cross sectional view of one form of a weightadapted to be positioned on the weight platform of FIGURE 14;

FIGURE 18 is a longitudinal view, taken in cross section of one form ofa bit guide for use in lowering a drill bit from the vessel to the oceanfloor; and,

FIGURE 19 is a longitudinal fragmental view of the hinge detail of thebit guide of FIGURE 18.

FIGURE 20 is an enlarged detail, taken in cross section, of one form ofa retractable support finger carried by the bit guide of FIGURE 18.

Referring to FIGURE 1 of the drawing, a drilling vessel, barge orplatform 11, of any suitable floating or floatable type is illustratedas floating on the surface of a body of water 12 while beingsubstantially fixedly positioned over a preselected well location bysuitable vessel positioning means well known to the art, or by beinganchored to the ocean floor 13 by anchor lines 14 and 15 running toanchors (not shown). Equipment of this type may be used when carrying onwell drilling operations or well work over operations in water varyingfrom about feet to 1500 feet or more in depth. The

drilling vessel 11 is equipped with a suitable derrick 16 containing afall line system 17 which includes a suitable hoist 18, traveling block19, and suitable hook or other conenctor means 20 adapted to connect tothe top of a large-diameter pipe, such as a well foundation pipe section21. The vessel 11 is also provided with other auxiliary equipment neededduring well-drilling operations, such for example, as a rotary tablepositioned on the operating deck, a hinge slip and spider assembly, etc.The derrick 16 is positioned over a drilling slot or well 22 whichextends vertically through the barge in a conventional manner. Whenusing the equipment of the present invention, a slot 22 in the vessel 11may be either centrally located or extend in from one edge.Alternatively, drilling operations may be carried out over the side ofthe vessel without the use of a slot. For example, the drilling vesselmay be provided with a deck portion which overhangs the hull of thevessel.

In FIGURE 2 the vessel 11 is shown as being provided with an auxiliarydeck 23 and an intermediate deck 24 within the slot 22. The cut-awayportion of the floor of the derrick 16 reveals one of the I-beams 25, itbeing understood that the floor of the derrick 16 employs a series ofparallel I-beams as a framework. Extending between two of thecountermost beams 25, and illustrated in FIGURE 2 as extending outwardlyfrom beam 25, are a pair of rotary-support beams 26 and 27 which arenormally employed to support a rotary table which rests on top of themand is secured thereto. The lower side of the rotary-support beams 26and 27 are provided with sling eyes 28 and 29, or any other suitabletype of connectors to which a pair of slings 30 and 31, tie rods, orother support means may be connected. The lower ends of the slings 30and 31 are secured to supports or sling eyes 32 and 33 that are weldedto the outer surface of the foundation pipe section 21. As shown inFIGURE 2 a second section 21a of the well foundation pipe 21 is about tobe lowered, as by means of the hoist system of the derrick, so that astabbing guide 34 carried at the end of the pipe section 21a is stabbedinto the top of the pipe section 21. The stabbing guide 34 may be in theform of a short section of pipe slightly smaller in diameter than thepipe sections 21 and 21a so that it can fit inside the pipe sections.The lower end of the stabbing guide 34 is preferably bevelled or cut atan angle as at 35 to facilitate the stabbing operation. After the twopipe sections 21 and 21a have been stabbed together they are fixedlysecured to each other, as by welding.

The number of sections of the well foundation pipe 2121a which arewelded together depends upon the length of the sections used and theoverall length of the well foundation pipe to be sunk in the oceanfloor. In one installation two 50-foot sections of large-diameter pipewere employed with the pipe diameter being in the order of 30 inches.After connecting the pipe sections together, the hoist sections of thederrick 16 is employed to lower the welded pipe and suspend it in amanner similar to suspending the single pipe section 21 in FIGURE 2.Thus, in FIGURE 3 the slings 30 and 31 secured to the sling eyes 28 and29 are temporarily connected at their lower end to a pair of sling eyes36 and 37 near the upper end of the uppermost pipe section 21a, as shownin FIGURE 3.

With the well foundation pipe 21-21a suspended from the rotary supportbeams 26 and 27 in a manner illustrated in FIGURE 3, a pair ofcross-support beams are arranged in spaced relationship and secured tothe rotary support beams 26 and 27. In FIGURE 3, only one of thecross-support beams 38 is illustrated. Secured to the top of thecross-support beam 38 and its parallel member (not shown) is a casingspider 40 of any suitable type well known to the art which employs slipsto fixedly position a pipe therein with the pipe hanging downwardly fromthe casing spider 40. In FIGURE 3 a wash pipe 41, preferably having ajet head 42 at the lower end thereof, is shown as being lowered, as bythe hoist system of the derrick 16, down through the central opening inthe casing spider 40, and thence downwardly into the open upper end ofthe well foundation pipe 21a. The wash pipe 41 is of smaller diameterthan the foundation pipe so that it may readily pass through it whileproviding annular space between the outer wall of the wash pipe 41 andthe inner wall of the foundation pipe 21-21a which serves as a returnfiuid passage in the apparatus of the present invention. A wash pipe inthe order of 9 inches in diameter may be used in a 30-inch foundationpipe 21-21a. The jet head 42 of the wash pipe 41 is shown in greaterdetail in FIGURE 12 as being provided with a series ofhorizontally-directed jet ports 43 and vertically-directed jet ports 44.Additionally, if desired, a series of spacer plates or centralizerplates 45 may be arranged vertically on the outer surface of the lowerportion 410 of the wash pipe 41. The horizontal dimension of the pipesection 41a and diametrically opposing centralizer plates 45 would beslightly less than the internal diameter of the well foundation pile21-21a so that the jet head and centralizer plates 45 could pass readilytherethrough while at the same time maintaining the jet head 42 insubstantially the center of the founda tion pipe 21-21a.

In addition to providing a conduit through which wash water can bepumped, the wash pipe 41 provides means for supporting the wellfoundation pipe 21-21a as it is being lowered from the vessel throughthe water into the ocean floor. In addition, the wash pipe 41 providesmeans for lowering and/ or supporting weights in contact with the top ofthe well foundation pipe 21-21a and subsequently removing the weightsfrom the pipe 21-21a after the pipe has been sunk to the desired depthin the ocean floor.

In FIGURE 4 the wash pipe 41 is shown as being lowered into positionwithin the upper section 21a of the well foundation pipe. The wash pipe41 has a suitable weight-transfer or weight-support member 46 and apipe-support member 47 fixedly secured thereto at definite spacedintervals on the outside of the pipe. The particular arrangement of pipesupport member 47 which is illustrated is designed to engage a J-slotcooperating support element 48 on the inner surface of the wellfoundation pipe 21a. The pipe support member 47 is shown in greaterdetail in FIGURE 13 as comprising a series of vertically-arranged andoutwardly-extending support arms 50. The overall spread of thediametricallyopposed support arms 50 is slightly less than the internaldiameter of the well foundation pipe 21a. A section of the wellfoundation pipe 21a is illustrated in FIGURE 15 as being provided with aseries of J-slot elements 48 arranged around the inner wall of the pipe.The space 51 between any two J-slot elements is sufficiently wide toallow the support arms 50 to pass between them. Thus, after a supportarm 50 passes down the space 51 between the J-slot elements 48, a slightrotation of the wash pipe 41 will rotate the support arm 50 across theend of the J and allow it to move upwardly into the closed portion ofthe J upon vertical movement of the wash pipe 41, in a manner shown inFIGURE 16. Alternatively, if the weight members are fixedly secured tothe wash pipe 41, then the weight-transfer or weight-support member 46and the pipe support member 47 may be one and the same element, forexample a J-slot device.

The weight-support member 46 (FIGURE 4) and the weights to be supportedthereon may take any form which can be readily handled on board adrilling vessel. One form of a weight-support member 46 is shown inFIGURE 14 as comprising upper and lower radially-extending plates 52 and53 arranged in spaced relationship and re-inforced by means ofvertically directed gussets 54 to which they are welded. Both of theplates 52 and 53 and the gussets 54 are fixedly secured, preferably asby welding, to the outer surface of the wash pipe 41 at a selecteddistance above the pipe support member 47 (FIGURE 4). The lower plate 53is perforated or of a form to permit circulation of fluid thereby. Thespacing between the weight-support member 46 and the pipesupport member47 must be such that the pipe support member 47 can be engaged in theJ-slot element 48 on the inner surface of the foundation pipe 21a whilethe weightsupport member 46 is above the top of the foundation pipe 21a.

One form of a weight element 55 is shown in greater detail in FIGURE 17as comprising an elongated cylindrical container 56 having closure meansat the top 57 and bottom 58 thereof and a vertical open-ended pipe 59along the axis of the container 56. The open-ended pipe 59 has aninternal diameter slightly greater than the outside diameter of the washpipe 41 so that the wash pipe can pass through it. Either the top 57 orthe bottom 58 of the container 56 may be removable so that the containermay be filled with a weighting material, such for example as barite, orthe container 56 may be provide with upper and lower closable openings60 and 61 which may be used for emptying and/or filling the container56. The openings 60 and 61 may be closed in any suitable manner, at bythreaded plugs. The container 56 is preferably provided with liftingeyes 62 whereby slings from the hoist system on the derrick can beconnected for lowering the weight container into place on the wash pipe41. A weight container feet high and four feet in diameter filled withbarite may weigh on the order 25,000 pounds. It is to be understood thatthe weight elements may take any other suitable form as large diameterdrill collars, hollow drill collars filled with a heavy material, cementpipe section, etc. which are positioned outside the wash pipe or form anintegral part thereof.

In FIGURE 6 the assembled apparatus is shown with three weightcontainers 55 positioned concentrically on a wash pipe 41, it beingunderstood that the wash pipe continues upwardly and is adapted toengage and be supported by the hoist system of the derrick in a mannerwell known in the art. At the same time, the upper end of the wash pipe41 is connected to a source of fluid pressure, such for example as apump which is positioned on the drilling vessel 11. As the wash pipe ispicked up (FIGURE 6) the slings 30 and 31 become slack and may bedisconnected. Subsequently, by removing the cross support beams 38, thewash pipe 41 and the weight containers 55 and be lowered downwardlythrough the deck 25. Obviously, the spacing between the rotary-supportmeans 26 and 27 must be greater than the diameter of the weightcontainers 55. Otherwise, the rotary-support beams 26 and 27 must beremoved temporarily until the weight containers have passed therethroughand then they would be re-installe d in the deck of the derrick, whenthe equipment is in the position shown in FIGURE 7.

The outer surface of the upper section 21a of the well foundation pipeis provided with two or more eyes 63 and 64 to which guide cables 65 and66 may be secured. This operation is usually done at the time the eyes63 and 64 pass the auxiliary deck 23 of the barge. It is is obvious thatthis operation can also be done at any time the equipment is above thesurface of the water. Preferably, a three-guide line system is employedalthough for ease of illustration only two of the guide lines will beshown. The guide lines 65 and 66 extend upwardly to a pair of winches 68and 69 which are mounted on the vessel at any suitable location, suchfor example, as on the intermediate deck 24. Preferably, the winches 68and 69 are constant tension hoists. If desired, the guide lines 65 and66 may pass through a pair of guide rings 70 and 71 havingvertically-directed openings, the rings being fixedly secured to theupper end of the foundation pipe section 21a, and serving to hold theguide cables against the pipe section 21a. If desired, the winches 68and 69 could be of a size and type adapted to be employed in loweringthe entire well foundation pipe 21 and 21a and the weight containers 55into place in the ocean floor either together with or independent of thewash pipe 41 which could be independently suspended by the hoist systemof the derrick. However, it is preferred that during the lowering andinstallation of the well foundation pipe 21-21a into the ocean floor,all of the weight be suspended by the wash pipe 41 when necessary andthat the guide lines 65 and 66 be only used for purposes as will bedescribed hereinbelow.

In FIGURE 8, the lower end of the lowermost section 21 of the wellfoundation pipe is illustrated as having entered the ocean floor. Sincethe top of the ocean floor is softer and more readily penetrated thanthe deeper formations, the great weight carried in the weight containers55 is sufficient to drive the well foundation pipes 21-21a to asubstantial depth instantaneously. However, it is desired that the earthcore that enters the bottom of the well foundation pipe section 21 as itis forced into the ocean floor be washed out of the interior of thefoundation pipe 21-21a so as to permit greater penetration by the pipe21-21a. It is for this purpose that the wash pipe 41 and its jet head 42is provided with fluid, such as salt water, which is pumped continuouslydown through the wash pipe to wash the earth particles from the interiorof the well foundation pipe 21-21a. The water is pumped down through thewash pipe 41, out the jet head 42, and circulates up the annular spacebetween the outside of the wash pipe 41 and the inside of the wellfoundation pipe 2121a and out the spaces in the lower plate 52 betweenthe gussets 54 of the weight support member 46 (FIGURE 14).

It is essential during this washing-out phase of the method of thepresent invention that the jet head 42 of the wash pipe not be immersedin soft formations to a depth such that it could not circulate thematerial up and out of the foundation pipe 21-21a. Thus, during theinitial washing-out stage, that is, as the foundation pipe first startsto penetrate the ocean floor, it is generally necessary to support aportion of the weight of the apparatus on the wash pipe and to slowlyfeed the wash pipe 41 and the surrounding foundation pipe 2121a into theocean floor. While it has not been mentioned hereinabove, one of themost important aspects of the method of the present invention is thatthere be a core of earth, generally represented by numeral 72 (FIG- URES8 and 9) in the bottom of the lower section 21 of the foundation pipe sothat at no time does any of the wash water jetting out of the jet head42 circulate down under the lower edge of the foundation pipe 21 andescape up the outside thereof to the surface.

While the escape of fluid in this manner would facilita-te the entry ofthe foundation pipe into the ocean floor, the resulting pipeinstallation would be of little use as a base pipe for an underwaterwell as the frictional resistance and/or holding power supplied by theformation bearing against the outer surface of the foundation pipe21-21a would be destroyed, thus reducing greatly the vertical loads thatthe foundation pipe could subsequently support. In order to maintain acore "72 in the bottom of the pipe 21 throughout the installationthereof, it is essential that the jet head 42 of the wash pipe 41 bepositioned at a determined distance above the lower end of the pipe 21so that water can escape up the outside of the pipe. In one giveninstallation the jet head 42 was positioned siX fee-t above the bottomof the foundation pipe 21; in another installation it was eight feetabove the bottom of the pipe 21. Accurate positioning of the jet head 42of the wash pipe 41 relative to the lower end of the foundation pipe 21can be accomplished by interconnecting the wash pipe 41 and the pipe2121a in any suitable manner, as by means of the J-sl'ot 48 and supportarms 50 as described hereinabove. Thus as the foundation pipe 2121apenetrates the ocean floor, the jet head 42 is at a known distance fromthe bottom of the foundation pipe 21.

While it is necessary to maintain a core 72 in the bottom of thefoundation pipe 21 throughout the installing procedures, it isespecially desirable that the core of earth 72 be kept as small aspossible to decrease the frictional resistance that it exerts on theinner wall of the foundation pipe 21 as increased resistance at thispoint decreases the depth to which the foundation pipe 21-2111 can besunk and hence lowers the amount of weight it could later support whenthe earth core 72 is drilled out during later drilling operations. Ithas also been found that the greatest penetration by a foundation pipecan be achieved by sinking the foundation pipe in a continuous operationto the depth desired. Thus, in the event that a hundred foot foundationpipe 21-21w is to be employed in the underwater well structure, twofifty foot sections 21 and 21a, respectively would be connectedtogether, as by welding, and loaded with weights so that they are forcedinto the ocean floor, with washing, in one continuous stroke. In someformations, if the moving foundation pipe is stopped during the pipesinking operation, it is impossible to start the pipe moving downwardlyagain even by the addition of extra weights. Thus, it is preferred thatthe entire length of foundation pipe be made up originally beforestarting the pipe sinking operation so that the sinking operations donot have to be stopped to add additional sections of pipe to the upperend thereof.

In FIGURE 9 the top of the foundation pipe 21-2111 has been sunk levelwith the ocean floor and the wash pipe, weight support member 46 andweights 55 are then withdrawn upwardly (FIGURE 10) after rotating andmanipulating the support arms 50 (FIGURE 13) out of the J-slot elements48 (FIGURE 15) to disengage it therefrom. If it is planned to use afoundation pipe 21-2111 with the upper end thereof flush with the oceanfloor and it is found later to be impossible to force the last portion,say feet of a hundred foot pipe section, into the ocean floor, an insidepipe cutter could be lowered on the running pipe string, similar to thewash pipe 41 except with a cutting head replacing the jet head 42, andthe inside pipe cutter could be manipulated to cut off the exposed upperend of the pipe and a fishing tool could be sent down on the lower endof a pipe string to pull the upper pipe section up along the guide lines65 and 66 (FIGURE 10) where it would be retrieved at the vessel.

With the foundation pipe 21-21:: in place in the ocean floor and theguide lines 65 and 66 extending from the foundation pipe to the vessel,drilling can be commenced by lowering a drill pipe 73 from the bargewith a bit 74 at the lower end thereof contained in a bit guide 75. Oneform of a bit guide is shown in FIGURE 18 as comprising a cylindricalhousing 76 comprising two halves hinged on one side by a hinge pin 77and provided on the other side with a connector pin 78 (FIGURE 19) forconnecting together the two halves 76 and 76a of the housing. Thehousing 76 is provided with an outwardly flaring skirt 79 at its lowerend to aid in positioning the bit guide on the upper end of a foundationpile 21a. Suitable means, such as slots 80 in the skirt 79 are providedfor slidably mounting the bit guide 75 on the guide lines 65 and 66(FIGURE 11). In addition to the slots 88 (FIGURE 19) channeliron guides86 are provided on the outside of the bit guide above the slots 80 tohold the guide lines with the use of removable keeper pins 87.

To position the bit guide 75 (FIGURE 18) on a drill bit 74, the bitguide is provided with two sets of latch fingers 81 and 82 which extendinto the bore of the bit guide 75 a distance sutficient so that theclearance between each set of latch fingers will not allow a bit to passtherethrough when the latch fingers are in their horizontally-extendedand operative position, as shown in FIGURE 18. As shown in FIGURE 20each latch finger is movable in a vertical plane about a horizontalpivot pin 83, but is normally held in the horizontally extended positionby means of a shear pin 84. Upon application of a predetermined weightto the latch fingers 82, the shear pins 84 break al- 8 lowing the bit 74(FIGURE 18) to pass downwardly through the bit guide and into thefoundation pipe 21a so that drilling operations can proceed. When thelatch fingers 82 move downwardly they move into vertical openings 85 cutin the wall of the housing 76a. Upon withdrawing the drill bit 74 fromthe well, the latch fingers 81 contact the bit as it is withdrawn pullthe bit guide back to the vessel in the event that the guide was notpreviously retrieved by a retrieving line. A string of well casing, withor without the casinghead attached to the top of it, can then be rundown into the place along the guide lines 65 and 66 by positioning thelower end of the well casing on the lower fingers 82 of the bit guide 75(FIGURE 18) and lowering it along the guide lines. The lower end of thewell casing would have a portion thereof similar to that shown in FIGURE2 with regard to the lower end of foundation pipe 21, which was largerin diameter than the rest of the pipe so that the enlarged portion wouldbe between the upper and lower latch fingers 81 and 82 so that the bitguide would not fall off the lower end of the casing. After the lowerend of the casinghead entered the foundation pipe 21a, in a mannerdescribed here-inabove with regard to a drill bit, a cable attached tothe connector pins 78 could pull the pin out and a bit/guide could beretrieved by means of a separate cable secured to another ring 86.

We claim as our invention:

1. A method of setting a well foundation pipe in an unconsolidatedformation underlying a body of water, said method comprising the stepsof (a) vertically suspending a foundation pipe from a floating vesselwith the lower end of said pipe extendmg into the body of water,

(b) positioning independent fluid conduit means with in said foundationpipe with said fluid conduit means extending downwardly from said vesseland centrally positioned in open spaced relationship within saidfoundation pipe, and connecting the fluid conduit means to saidfoundation pipe so that the lower end of said conduit means is adjacentbut above the lower end of said foundation pipe,

(c) lowering said fluid conduit means and said foundat1on pipe until thepipe contacts the formation below said body of water,

(d) sinking said foundation pipe together with said fluid conduit meanspositioned therein into said unconsolidated formation,

(e) simultaneously pumping fluid down said central conduit means intothe bottom of said foundation pipe to disintegrate and wash out theformation core entering the bottom of the foundation pipe as said pipeis forced into said formation, and

(f) circulating all of said pumped fluid and formation washings up thefoundation pipe and through the annular flow passage outside saidconduit means while maintaining the end of said conduit means a distanceabove the lower end of said pipe so that a core of said formationremains in the bottom of said pipe at all times preventing the escape offluid therefrom.

2. The method of claim 1 including the steps of suspending saidfoundation pipe in open concentric spaced relationship from said fluidconduit means and outside thereof while suspending said conduit meansfrom said vessel.

3. The method of claim 1 including the step of removably connecting thefoundation pipe to said conduit means in a rigid manner so that thelower end of said conduit means is at a fixed distance above the lowerend of said pipe as the two are lowered together into the underwaterformation.

4. The method of claim 1 including the step of forcing said foundationpipe together with said fluid conduit means positioned therein into saidformation by applying a weight positioned adjacent said conduit means tosaid pipe.

5. The method of claim 1 including the steps of continuing sinking saidfoundation pipe into said formation and washing the core therefrom untilthe top of said foundation pipe is at the desired level relative to saidformation, and subsequently removing said conduit means from saidfoundation pipe.

6. The method of claim 1 including the steps of sinking said foundationpipe into said formation to refusal while washing the core therefrom,removing the conduit means from said foundation pipe, and subsequentlycutting off the upper portion of said foundation pipe at the desiredlevel relative to said formation.

7. A method of setting a well foundation pipe in an unconsolidatedformation underlying a body of water, said method comprising the stepsof (a) locating a floating vessel over the underwater formation,

(b) substantially fixedly positioning said vessel at said location,

(c) making up a foundation pipe on said vessel,

(d) vertically suspending said foundation pipe from said vessel with thelower end of said pipe extending into the body of water,

(e) installing fluid conduit means extending downwardly from said vesseland centrally positioned in open concentric spaced relationship withinsaid foundation pipe with the lower end of said conduit means adjacentbut above the lower end of said foundation p p (f) transferring thesuspension of said foundation pipe from said vessel to the outside ofsaid fluid conduit means in open spaced relationship therewith whilesuspending said conduit means from said vessel,

(g) lowering said fluid conduit means and said foundation pipe until thepipe contacts the unconsolidated formation below said body of water,

(h) forcing said foundation pipe together with said fluid conduit meanspositioned therein into said formation by applying a weight to saidpipe,

(i) simultaneously pumping fluid down said central conduit means intothe bottom of said foundation pipe to wash out the formation coreentering the bottom of the foundation pipe as said pipe is forced intosaid formation,

(j) circulating all of said pumped fluid and formation washings up thefoundation pipe and through the annular flow passage outside saidconduit means while maintaining the end of said conduit means a distanceabove the lower end of said pipe so that a core of said formationremains in the bottom of said pipe at all times preventing the escape offluid therefrom, and

(k) continuing forcing said foundation pipe into said formation andwashing the core therefrom until the top of said foundation pipe is atthe desired level rel ative to said formation.

References Cited by the Examiner UNITED STATES PATENTS 1,173,355 2/16Jones 61-53:.74 1,512,140 10/24 Schaub 175-67 X 1,853,379 4/32 Rotinotf175-67 X 2,010,199 8/35 Rotinoff 175-60 X 2,684,575 7/54 Pryor et a1.16666.5 2,756,020 7/56 dAudiflret et al. 175-67 2,891,770 6/59 Bauer etal 1757 2,906,500 9/59 Knapp et al 166--66.5 2,931,187 4/60 Perkins17567 X 35 CHARLES E. OCONNELL, Primary Examiner.

1. A METHOD OF SETTING A WELL FOUNDATION PIPE IN AN UNCONSOLIDATEDFORMATION UNDERLYING A BODY OF WATER, SAID METHOD COMPRISING THE STEPSOF (A) VERTICALLY SUSPENDING A FOUNDATION PIPE FROM A FLOATING VESSELWITH THE LOWER END OF SAID PIPE EXTENDING INTO THE BODY OF WATER, (B)POSITIONING INDEPENDENT FLUID CONDUIT MEANS WITHIN SAID FOUNDATION PIPEWITH SAID FLUID CONDUIT MEANS EXTENDING DOWNWARDLY FROM SAID VESSEL ANDCENTRALLY POSITIONED IN OPEN SPACED RELATIONSHIP WITHIN SAID FOUNDATIONPIPE, AND CONNECTING THE FLUID CONDUIT MEANS TO SAID FOUNDATION PIPE SOTHAT THE LOWER END OF SAID CONDUIT MEANS IS ADAJCENT BUT ABOVE THE LOWEREND OF SAID FOUNDATION PIPE, (C) LOWERING SAID FLUID CONDUIT MEANS ANDSAID FOUNDATION PIPE UNTIL THE PIPE CONTACTS THE FORMATION BELOW SAIDBODY OF WATER, (D) SINKING SAID FOUNDATION PIPE TOGETHER WITH SAID FLUIDCONDUIT MEANS POSITIONED THEREIN INTO SAID UNCONSOLIDATED FORMATION, (E)SIMULTANEOUSLY PUMPING FLUID DOWN SAID CENTRAL CONDUIT MEANS INTO THEBOTTOM OF SAID FOUNDATION PIPE TO DISINTEGRATE AND WASH OUT THEFORMATION CORE ENTERING THE BOTTOM OF THE FOUNDATION PIPE AS SAID PIPEIS FORCED INTO SAID FORMATION, AND (F) CIRCULATING ALL OF SAID PUMPEDFLUID AND FORMATION WASHING UP THE FOUNDATION PIPE AND THROUGH THEANNULAR FLOW PASAGE OUTSIDE SAID CONDUIT MEANS WHILE MAINTAINING THE ENDOF SAID CONDUIT MEANS A DISTANCE ABOVE THE LOWER END OF SAID PIPE SOTHAT A CORE OF SAID FORMATION REMAINS IN THE BOTTOM OF SAID PIPE AT ALLTIMES PREVENTING THE ESCAPE OF FLUID THEREFROM.